A Microsoft spokesperson refused to comment on the screenshots, and said the company has nothing to share about future versions of Windows at this time.

But if they're real, two things stand out.

It's called the Windows App Store. Last month, Microsoft tried to stop Apple from trademarking the term "App Store," saying it was too generic.

The screenshots appear to be running on Windows 7, which suggests the App Store might not be a Windows 8 exclusive.

Although Microsoft will probably be accused of imitating Apple, in fact the company had an app store called the Windows Marketplace built into the Start menu on Windows Vista, along with a secure digital locker for storing purchased apps.

But it never got much use -- the link was too hidden, and developers figured they would get more traction from guiding users to their own Web sites. So Microsoft shut down the Windows Marketplace site in 2008, turning it into a referral site instead.